frmfft.frm

快速傅立叶变换

VERSION 5.00
Begin VB.Form frmFFT 
   Caption         =   "Form1"
   ClientHeight    =   7845
   ClientLeft      =   825
   ClientTop       =   1335
   ClientWidth     =   13800
   LinkTopic       =   "Form1"
   ScaleHeight     =   7845
   ScaleWidth      =   13800
   Begin VB.ListBox ListRlt 
      Height          =   7260
      Left            =   8820
      TabIndex        =   6
      Top             =   270
      Width           =   2145
   End
   Begin VB.ListBox ListR2 
      Height          =   7260
      Left            =   13170
      TabIndex        =   5
      Top             =   210
      Width           =   2145
   End
   Begin VB.ListBox List0 
      Height          =   7260
      Left            =   2130
      TabIndex        =   4
      Top             =   330
      Width           =   2145
   End
   Begin VB.ListBox ListR1 
      Height          =   7260
      Left            =   10920
      TabIndex        =   3
      Top             =   240
      Width           =   2145
   End
   Begin VB.ListBox ListImage 
      Height          =   7260
      Left            =   6630
      TabIndex        =   2
      Top             =   270
      Width           =   2145
   End
   Begin VB.ListBox ListReal 
      Height          =   7260
      Left            =   4470
      TabIndex        =   1
      Top             =   270
      Width           =   2145
   End
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   945
      Left            =   120
      TabIndex        =   0
      Top             =   1650
      Width           =   1575
   End
End
Attribute VB_Name = "frmFFT"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit

Private Const PI = 3.14159265358979
Private Const NUMBER = 64

Private Sub Command1_Click()

    Dim RealIn(1 To NUMBER) As Single, ImagIn(1 To NUMBER) As Single
    Dim RealOut(1 To NUMBER) As Single, ImagOut(1 To NUMBER) As Single
    
    Dim i As Integer, j As Integer
    
    List0.Clear
    For i = 1 To NUMBER
        RealIn(i) = Exp(-0.1 * (i - 1))     'Cos(CSng(2) * PI * (i - 1) / NUMBER + 0) ' + 0.3 * Sin(CSng(2) * PI * (i + 3) / 256 + 0)
        ImagIn(i) = 0       ' -Cos(CSng(2) * PI / NUMBER * (i - 1))
        List0.AddItem RealIn(i)
    Next i
    
    Call FFTSingle(NUMBER, False, RealIn(1), ImagIn(1), RealOut(1), ImagOut(1))
     
    ListReal.Clear
    ListImage.Clear
    For i = 1 To NUMBER
        ListReal.AddItem RealOut(i)
        ListImage.AddItem ImagOut(i)
    Next i

    Dim fl1 As Single, fl As Single
    ListRlt.Clear
    For j = 1 To NUMBER
        fl = 0
        For i = 1 To NUMBER
            fl = fl + RealOut(i) * (Cos((ImagOut(i) * (j - 1)) * CSng(2) * PI / NUMBER) - _
                Sin((ImagOut(i) * (j - 1)) * CSng(2) * PI * (j - 1) / NUMBER))
        Next i
        ListRlt.AddItem fl / NUMBER
    Next j

    For i = 1 To NUMBER
        RealIn(i) = RealOut(i)
        ImagIn(i) = ImagOut(i)
    Next i

    
    Call FFTSingle(NUMBER, True, RealIn(1), ImagIn(1), RealOut(1), ImagOut(1))
    
    
    ListR1.Clear
    ListR2.Clear
    For i = 1 To NUMBER
        ListR1.AddItem RealOut(i)
        ListR2.AddItem ImagOut(i)
    Next i
    
    
    

End Sub

Private Sub Command2_Click()
    
End Sub